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Biomedical subjects

C W McIntyre

Publications and source records attributed to C W McIntyre.

At least 19 recordsLinked to original sources
PubMed1999

Effects of new analogues of vitamin D on bone cells: implications for treatment of uremic bone disease.

BACKGROUND: The use of calcitriol in the treatment of uremic hyperparathyroidism and renal osteodystrophy is limited in many patients by hypercalcemic side-effects. New less calcemic analogues of calcitriol are being developed, and some are under clinical evaluation. To investigate whether these compounds possess important differences in their action on bone cells, we have studied their effects [with and without parathyroid hormone (PTH)] on the release and synthesis of the resorptive osteotropic cytokine, interleukin-6 (IL-6). METHODS: MG 63 and SaOS-2 human osteoblastic cell lines were cultured for 6 or 24 hours in media containing calcitriol, the sterols of interest, or 1-34 synthetic PTH. IL-6 release was assayed by commercially available enzyme-linked immunosorbent assay. IL-6 mRNA levels were assessed by reverse transcriptase-polymerase chain reaction. RESULTS: We found that calcitriol and paricalcitol behaved in a similar fashion, resulting in increased IL-6 release only at higher concentrations (10(-7) to 10(-9) M). In contrast, 22-oxacalcitriol and 1,25-dihydroxydihydrotachysterol2 stimulated release to a similar extent but at concentrations three to four orders of magnitude lower (10(-11) to 10(-13) M), despite being less potent as suppressers of parathyroid function than calcitriol. Studies of IL-6 mRNA showed a similar pattern of concentration and cell line-dependent transcription. CONCLUSIONS: Compounds stimulating IL-6 release at concentrations achievable during the treatment of uremic hyperparathyroidism might favor continuing linked bone formation and resorption and thereby avoid adynamic bone disease while still allowing profound suppression of PTH.

Bone Diseases↗
PubMed1995

Prostate-specific antigen levels in patients receiving long-term dialysis.

OBJECTIVE: To investigate the effect, if any, of renal failure upon prostate-specific antigen (PSA) levels and the validity of PSA estimation as a marker of prostatic disease in renal failure. PATIENTS AND METHODS: PSA was measured in 65 men (median age 67 years, range 39-84) on regular haemodialysis and 37 men (median age 70 years, range 42-77) on continuous ambulatory peritoneal dialysis (CAPD). Patients with a PSA level > 4 ng/mL underwent prostatic biopsy guided by transrectal ultrasonography. RESULTS: There was no evidence of an artefactual elevation of PSA attributable solely to renal failure. All eight patients with a PSA level > 4 ng/mL had prostatic disease. CONCLUSION: PSA measurements in patients with end-stage renal failure treated by dialysis remain a useful marker of prostatic disease.

Adult↗
PubMed1992

Affect, personality, and social activity.

These studies examined relations between social activity and state and trait measures of Positive and Negative Affect. In Study 1 Ss completed scales relevant to 3-factor models of personality and a weekly mood and social activity questionnaire for 13 weeks. In Study 2 Ss completed measures of the 5-factor model of personality and a daily mood and social activity survey for 6-7 weeks. In within- and between-Ss analyses, socializing correlated significantly with state measures of Positive Affect and with trait measures of Extraversion/Positive Emotionality. These relations were relatively general across various types of positive affect and social events; however, specific types of social events also were differentially related to affect. In contrast, social activity had no consistent association with measures of Negative Affect or the other personality dimensions. The results support a temperamental view of Extraversion.

Adult↗
PubMed1989

Visual and auditory coding confusability in students with and without learning disabilities.

The nature of visual and auditory coding processes in students with learning disabilities (SLDs) and student controls (SCs) was examined with a letter-matching task on four types of successively presented letter pairs: identical (A,A), visually confusable (P,R), auditorily confusable (F,S), and neither visually nor auditorily confusable (N,T). Two delay intervals (0 and 2 seconds) were used between the presentation of the first and second letters. Analysis of decision latencies on the nonidentical letter pair trials revealed that with initial exposure to the task, the SLDs responded more slowly than SCs, but their general confusability patterns (visual and auditory) were similar. With additional practice, overall decision latencies were comparable for the two groups, while confusability differences emerged: SCs showed maximal visual confusability at a 0-second delay and maximal auditory confusability at a 2-second delay, while SLDs did not. Evidently, SLDs make less extensive use of visual and auditory coding processes compared to SCs.

Attention↗
PubMed1986

Birth order effects in second-generation alcoholics.

The effects of birth-order position (first-, middle- and last-born) in intact families with three children on the psychopathology scores of second-generation alcoholics were examined by administering the MMPI to 90 alcoholic sons of alcoholic parents. Analyses of variance (ANOVAs) applied to the individual MMPI scale scores revealed a consistent pattern of results: first borns evidenced significantly less exaggerated psychopathology scores than both groups of later borns. Most of the extreme scale scores obtained within this population of alcoholics were obtained from the later borns. Implications for previous generalizations about the alcoholic children of alcoholic parents are discussed.

Adult↗
PubMed1985

Neuroleptic malignant syndrome.

The neuroleptic malignant syndrome (NMS) is a potentially fatal complication of antipsychotic drugs. It is characterized by severe muscular rigidity, hyperthermia, and autonomic disturbances. Neuroleptic malignant syndrome is easily confused with other health problems; distinctions between it and malignant hyperthermia, heatstroke, and lethal catatonia are made. The relevant literature is reviewed; a case history is presented; and implications for nursing care (e.g., early detection) are discussed.

Adult↗
PubMed1983

Information processed from brief visual displays by learning-disabled boys.

The spans of apprehension of learning-disabled and normal boys were compared by means of a forced-choice letter-recognition task involving tachistoscopic exposures of letter displays. This task provides an estimate of the span that is relatively insensitive to memory or motivational influences. In Experiment 1, the spans of learning-disabled and normal boys were compared under 4 information conditions: with no noise letters present or with 2, 4, or 8 noise letters present. Experiments 2-4 examined 3 possible interpretations of the deficit in the span of apprehension observed for learning-disabled boys in Experiment 1. In Experiment 2, the possibility that the noise letters were more distracting for learning-disabled boys was examined by varying the amount of physical similarity and redundancy between the signal and noise letters. In Experiment 3, the possibility that the visual afterimage of the letter displays faded more rapidly for the learning-disabled boys was examined. In Experiment 4, the possibility that the learning-disabled boys were slower to pick up information from the decaying afterimages was examined. The results of these three experiments indicated that the decreased spans of apprehension observed for the learning-disabled boys in Experiment 1 resulted either from greater distractiveness or from the slower pickup of information, or both. The implications for visual training are discussed.

Attention↗
PubMed1978

Span of apprehension in hyperactive boys.

The spans of apprehension of hyperactive and normal boys were compared with a forced-choice letter-recognition task developed by Estes (1965). This task provides an estimate of the span which is relatively insensitive to either memory or motivational influences. The span size was the same for both groups when visual "noise" was absent. In the presence of noise, span size for the hyperactive boys decrease. Moreover, as the number of noise letters increased, the reduction in span size observed for the hyperactive boys increased. It is argued that this increasing reduction in span size represents a true deficit in attention.

Afterimage↗
PubMed1978

Effect of noise distractibility on the spans of apprehension of hyperactive boys.

Denton and McIntyre (1978), using a forced-choice letter-recognition procedure, demonstrated increasing reductions in the spans of apprehension of hyperactive as compared to normal boys when a signal letter was embedded within an increasing number of noise letters. In the present study, the effect of variations in the amount of physical signal-noise similarity and noise redundancy upon the spans of apprehension of hyperactive and normal boys was compared to determine whether noise letters act as more potent distractors for the hyperactive boys. Results indicated the spans of both groups were effected equivalently by variations in signal-noise similarity and noise redundancy. No evidence for a distractibility explanation was obtained.

Attention↗
PubMed1976

The content and manipulation of cognitive maps in children and adults.

Comparison of cognitive maps generated by first graders, fifth graders, and college students using a triangulation task revealed that the first graders possessed very accurate, coherent cognitive maps. However, analyses of the cognitive maps generated when Ss were asked to imagine either the room rotating (mental rotation) or themselves moving within the room (perspective-taking) revealed that the accuracy and completeness of the mental manipulation increased dramatically with age. Only the cognitive maps of the college students were coherent and accurate during mental rotation than during perspective-taking. Careful attention was given to the types of errors made, and several systematic error patterns were identified which reflected qualitative differences. These qualitative differences indicated mental manipulation was a two-stage process. In the first stage, a strategy of transformation was applied to the ordinal spatial relationships contained within the cognitive map. First graders evidenced difficulty here. In the second stage, more specific relationships between self and spatial layout were reconstructed. Fifth graders evidenced difficulty here. In contrast, college students were able to complete both stages of the process.

Adolescent↗